The sling was made of leather, or of plaited work of wool, rushes, hair, or sinews. The middle part, where the stone lay, was called the cup (caph), because of its cup-like depression. It was wider than the ends, but the sling gradually narrowed toward the extremities, so that it could be easily handled. In the Egyptian sling, which probably was the same as the Hebrew, there was a loop at one end which was placed over the thumb, in order to retain the weapon when the stone was hurled and the other end became free. The sling was used by shepherds to keep the beasts of prey from the flock, and also to keep the sheep from straying. Husbandmen likewise used it to drive away birds from the fields of corn. In war it was a formidable weapon in skillful hands. The Egyptian ginger carried a bag of round stones depending from his shoulder, as David did. The Assyrians, however, according to their sculptures, had lying at their feet a heap of pebbles, which they picked up as they were needed. In using the sling, the stone was put into the broad hollowed part, the ends were grasped together in the hand, and after a few whirls around the head to give impetus, the stone was discharged, frequently with force enough to penetrate helmet or shield.